At 48 months, 82.5% of amlodipine and 77.8% of acebutolol patients remained on monotherapy, which was significantly higher than placebo (P<0.01).
Does adherence to anti-hypertensive drug therapy improve clinical outcomes and reduce healthcare costs in hypertensive patients?
Poor adherence to anti-hypertensive therapy leads to inadequate blood pressure control, higher mortality, and increased healthcare costs, highlighting the need for strategies to improve long-term compliance.
p-value: p=< 0.01
Long-term adherence or compliance with anti-hypertensive drug therapy is poor. It has been estimated that within the first year of treatment 16-50% of hypertensives discontinue their anti-hypertensive medications. Even among those who remain on therapy long term, missed medication doses are common. Epidemiological studies have shown that drug-treated hypertensives have higher blood pressures than age-, gender- and body mass index-matched normotensives. In addition, drug-treated hypertensive men and women who achieve blood pressure normalization are less likely to die over a 9.5-year period than those whose blood pressure remains elevated while taking anti-hypertensive drugs. Thus, one reason for less than optimal reduction of blood pressure-related cardiovascular-renal risk in drug-treated hypertensives is inadequate blood pressure lowering. Quantifiable excess risk has been documented even in the short term ( < 1 year) after interruption or discontinuation of anti-hypertensive medications as total healthcare costs are higher, mostly because of higher hospitalization rates. Data from the Treatment of Mild Hypertension Study (TOMHS) are relevant to long-term adherence to various anti-hypertensive drug monotherapies. At 48 months, 82.5% and 77.8% of participants remained on amlodipine and acebutolol, respectively (both P < 0.01 compared with placebo). However, only 67.5%, 66.1% and 68.1%, respectively, of chlorthalidone, doxazosin and enalapril participants remained on these drugs as monotherapy at 48 months. Differential adherence to long-term anti-hypertensive drug therapy could translate into a greater risk of blood pressure-related complications and higher overall healthcare expenditures. Strategies to minimize the deleterious impact of therapeutic non-adherence with anti-hypertensive medications as well as the clinical and cost implications of the TOMHS data will be discussed.
“Fear of adverse events remains a major reason for undertreatment of high blood pressure, the leading modifiable risk factor for death and cardiovascular disease worldwide. For years, we have assumed that more blood pressure-lowering treatment equates to worse tolerability, and hence most patients are started and remain on single drug monotherapy. This was highly surprising because few treatments in medicine are better tolerated than placebo, let alone when you combine two active treatments together.”
Flack et al. (1996) conducted a review in Hypertension. Anti-hypertensive drug therapy vs. Placebo was evaluated on Remaining on drug as monotherapy at 48 months (p=< 0.01). At 48 months, 82.5% of amlodipine and 77.8% of acebutolol patients remained on monotherapy, which was significantly higher than placebo (P<0.01).